The Ace of Spades was Hippy Flipping.
Ace of Spades' Hobby
Explanation
Explain Bear
Listen, you knucklehead, let me break it down for you. "Hippy Flipping" is when you take shrooms and molly at the same time. The Ace of Spades is a card in a deck, and here it's personified to be doing drugs, get it?